Illuminated warning device with switchoperating mechanism



y 1953 D. M. HALLERBERG ILLUMINATED WARNING DEVICE WITH SWITCH-OPERATING MECHANISM 3 Sheets-Sheet 1 Filed May 22, 1961 INVENTOR. DON M. HALLERBERG BY 9 2 ATTORNEYS May 21, 1963 D. M. HALLERBERG ILLUMINATEZD WARNING DEVICE WITH SWITCH-OPERATING MECHANISM 3 Sheets-Sheet 2 Filed May 22. 1961 i'ball'llll I'll,

dyer? LEE IN VEN TOR. HALLERBE RG DON M.

ATTORNEY$ May 21, 1963 n. M. HALLERBERG ILLUMINATED WARNING DEVICE WITH SWITCH-OPERATING MECHANISM 3 Sheets-Sheet 5 Filed May 22. 1961 'II'I/I/l'llI/I/IIJA INVENTOR. HALLERBERG DON United States Patent 3,0Sl0,949 ILLUMINATED WARNING DENICE WITH SWITCH- OPERATING MECHANISM Don M. Hallerberg, Los Angeles, Calif. (2009 Suana Drive, San Pedro, Calif.) Filed May 22, 1961, Ser. No. 111,866 14 Claims. (Cl. 340-666) I This invention relates to an illuminated signal or warning device which has a built-in switch-operating mecha- IllSlTl and more specifically to certain structural improve ments therein.

Warning devices of the general type with which the present invention is concerned are commonly used in large control panels of various types for monitoring installations and also in aircraft to indicate conditions of abnormality, such as the malfunction of a particular circurt or a landing gear mechanism, for example. A lamp within the warning light device either can be lighted when an abnormal condition occurs or can burn steadily and be extinguished when the abnormal condition occurs. In either case, however, the device must be highly reliable because a failure to indicate the condition of abnormality may result in the over-all failure of the object or system being monitored through a control panel or may result in an accident to an aircraft in which the device is used.

To achieve as high a degree of reliability as possible, the warning light devices usually are provided with lamp test circuits which can be built into or associated with the device to test quickly the lamps therein to determine if a lamp is extinguished because of a change in a condition to which it is intended to be responsive, or because of failure of the lamp.

If any lamp is found to be burned out, as often occurs with the small lamps usually used in such devices, replacement or rebulbing must be accomplished easily and rapidly from the front of the panel in which the device is mounted, so that the status of the condition being monitored can be determined again with minimum interruption.

Heretofore, warning light devices with rotatable lamp capsules have been employed to facilitate the rebulbing step. However, in these devices, the capsules always remain attached to the housing of the device and cannot be separated therefrom; consequently, the new lamps must be carried to the devices, the old lamps removed, and the new ones inserted. Because the lamps are small, and because the warning devices are sometimes located in rather inaccessible places, such as down near the floor of a panel or behind control post of an airplane, the rebulbing operation is sometimes quite difficult to achieve.

The present invention provides an improved warning light device which overcomes the above difiiculty. The lamp unit can be removed completely from the warning device so that an operator can carry it to a more accessible location, at which he can remove the defunct lamps and insert the new ones. The lamp unit can then be moved back to the warning device and quickly assembled therewith.

In previously known warning light devices of the type heretofore described, the devices occasionally must be removed from. the panel in which they are mounted to replace a defective device or to change the switch units attached to the rear of the devices. Heretofore, such warning light devices could be removed only from the back of the panel. This was very diflicult to achieve at times, particularly where a large number of such devices were used in a large control panel along with other controls. Even when the back of the panel was easily accessible, removal of a warning light device was a relatively timeconsuming operation.

The new warning light device is provided with a panelmounting arrangement which enables the device to be re- 3,090,949 Patented May 21, 1963 ice moved and re-mounted entirely from the front of the panel regardless of the accessibility to the back thereof. The removal is easily accomplished simply by loosening two screws which become easily accessible upon removal of the lamp capsule.

Previously known warning light devices have been provided with switches and built-in switch-operating mechanisms which are operable from obverse faces of the devices. The switches themselves heretofore have been built into the devices and made integral parts thereof. Consequently, if the switch was to be changed, for example from a six terminal switch to an eight terminal switch or from normally-open switches to normally-closed switches, the entire warning device had to be replaced.

In contrast, in the new warning light device according to the invention, the switch can simply be snapped onto the back of the warning light device so that a change can be effected simply by snapping off the old switch and replacing it with the desired one and, of course, changing the wires connected thereto. The snap-on feature of the new warning light device is designed so that the replaceable switch can only be snapped on in one given position, to eliminate any possibility of improper assembly.

The new warning light device also has special springloaded lamp contacts which provide a more positive electrical contact with the lamps. The lamps themselves are provided with plastic domes which are mounted around the bulbs of the lamps and are spaced therefrom to enable light of a desired color to be transmitted through an obverse face of the device from each lamp, without the necessity of using colored panels on the face thereof. By spacing the plastic domes slightly away from the bulbs of the lamps, with an air space therebetween, heat from the lamp can be dissipated more rapidly so that the lamp will be at a lower temperature and will have a longer life. There is also a lesser tendency for the plastic dome itself to overheat and to stick to the lamp bulb.

It is, therefore, a principal object of the invention to provide an improved warning light device with a built-in switch-operating mechanism having the features and advantages outlined and discussed above.

Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which:

FIG. 1 is a view in perspective of an illuminated warning device embodying the constructional features of the invention;

FIG. 2 is a view in longitudinal cross section of the warning device, taken along the line 2-2 of FIG. 1, and of a portion of a panel in which the device is mounted;

FIG. 3 is a view in cross section similar to FIG. 2 but with a switch-operating mechanism and sign panel pulled out and turned FIG. 4 is a view in cross section taken along the line 44 of FIG. 2;

FIG. 5 is an exploded view of the over-all warning device;

FIG. 6 is an exploded view in perspective of a lampmounting plate shown in FIGS. 2-5;

FIG. 7 is a view in perspective of a switch-operating rod shown in FIGS. 2-5;

FIG. 8 is a. view in perspective of a resilient lamp contact for electrically engaging the lamps shown in FIGS. 2, 3 and 5;

FIG. 9 is a detailed view in cross section of a switch unit and means for removably attaching the switch unit to a housing of the warning device;

FIG. 10 is a view in perspective of a portion of the warning device and of means for mounting the warning device on a control panel or the like;

FIG. 11 is a view in perspective of the Warning device with modified means for mounting the device on a panel;

FIG. 12 is a detailed view of a portion of the panelmounting means taken along the line 12-12 of FIG. ll; and

FIG. 13 is a detailed view in cross section of a lamp employed in the warning device and its surrounding dome.

Referring to the drawings, and more particularly to FIG. 1, an illuminated warning device indicated at 20 includes an obverse face constituting a translucent sign panel 22 carrying suitable indicia, and a housing 24 for lamps and a switch-operating mechanism used to actuate a switch unit 26. Referring more particularly to FIGS. 2 and 3 and to the interior of the housing 24, the switchoperating mechanism includes a bracket 28 which carries the sign panel 22 and a switch-operating rod 30. The rod 30 extends through a rear wall 32 of the housing 24 and operates the switch unit 26 when the bracket 28 and the sign panel 22 are pushed inwardly from the position of FIG. 2. The switch unit 26 can contain many types of switches, of course, with many variations in terminals and in opening and closing sequences.

The switch rod 30 also extends through an insulating partition 34 holding lamp contacts 36 and 38, to be discussed in detail subsequently, which electrically connect lamps 40 to hot terminals 42 and a ground terminal 44 (FIG. 3). The terminals 42 and 44 can be wired so that the lamps 40 will operate individually, in pairs, or all together to indicate the status of a condition or several conditions being monitored. The lamps 40 can also be wired to light upon the occurrence of a certain change in the condition or to burn steadily and to be extinguished when the change occurs.

The lamps 40 are held in a mounting plate 46 which moves outwardly with the switch-operating rod 30 when the rod 30 is twisted 90 and is pulled outwardly with the bracket 28 beyond the position shown in FIG. 3. This action releases a locking device (subsequently described) within the mounting plate 46 which enables it to be separated from the housing. Thus, the mounting plate 46 and the lamps 40' can be separated completely from the housing 24, which is particularly advantageous when the device 20 is located in an inconvenient position. In such a case, the entire lamp assembly of the bracket 28, the sign panel 22, the switch-operating rod 30, the plate 46, and the lamps 40 can be withdrawn from the housing 24, and carried to a more accessible location at which the lamps 40 can be more easily and conveniently changed. This is especially advantageous because the lamps 40 used in the warning devices usually are very small and hard to handle.

The lamp mounting plate 46 and a preferred form of the locking device carried thereby will now be explained in more detail. Referring more particularly to FIG. 6, the lamp mounting plate 46 actually consists of seven layers or laminations including six reinforced resinous layers and a metal one. All seven layers contain openings 48 in which the lamps 40 are located and all seven layers contain a central opening through which the switchoperating rod 30 extends. An upper layer 50 includes a small central hole 52 which is just slightly larger than the diameter of the rod 30. A second layer 54 includes a small central opening 56 for the rod 30 and also an elongated, bow-shaped opening 58 in which a wire spring 60 is mounted so that a central part of the spring 60 extends slightly into the central opening 56. The spring 60 helps to control movement of the rod 30, as will be explained more fully subsequently. A third layer 62 of the plate 46 is similar to the plate 50 and includes a small central hole 64 which is slightly larger than the rod 30. The next, or fourth, layer 66 and a fifth layer 68 each consists of two separate sections 70 which are identical. The sections 70 include the openings 48 for the lamps 40 and central notches 72 forming a large central opening which is much larger than the openings 52, 56 ,and 64,

and is much larger than the diameter of the rod 30. The sections are spaced from one another to form recesses 74 which extend perpendicularly to the longitudinal extent of the plate 46 and also extend radially to the central openings formed by the notches 72.

The recesses 74 receive a metal liner 76 which has a central opening 78 including two notches 80; the liner 76 also includes bent up cars 82 which form end abutments for small springs 84 (FIG. 4) or other suitable resilient means which are located between legs 86 of locking tangs 88. The springs 84 urge the tangs 88 inwardly to a position such that the legs 86 are within the confines of the recesses 74 of the plate 46. An oblong cam member 90 is positioned on the liner 76 in the central opening formed by the notches 72, the cam member having a central elongate opening 92 which is properly sized to receive a pin 94 aflixed to and extending laterally of the switch operating rod 30, when the rod 30 is in the outer position, as shown in FIG. 3.

When the cam member 90 is perpendicular to the longitudinal extent of the plate 46 and is parallel to the long walls of the recesses 74, it overcomes the force of the springs 84 and urges the locking tangs 88 outwardly so that the legs 86 extend slightly beyond the plate 46 and, more specifically, beyond recesses 96 which are formed in the plate 46 by notches in the individual layers. In this position, the tips of the legs 86 extend under ridges 98 (FIGS. 4 and 5) which are formed on the housing 24 and extend inwardly therefrom. The tangs 88 and the projections 98 thus cooperate to lock the plate 46 in the housing 24 and prevent it from being separated therefrom as long as the locking legs 86 are cammed outwardly.

Below the layer 70 is a fifth layer 100 which has a large central opening 102, the diameter of which is greater than the length of the pin 94 so that the pin can pass therethrough. The lowest layer is a metal sheet 104 through which the lamps 40 extend, the lamps 40 being frictionally held in tubular housings or sockets 106 (FIG. 13) each of which is held in the plate 46 by an upper annular flange 108 and a lower ring 110 which also ilectrically connects the tubular housing 106 to the plate The operation of the switch-operating rod 30 and the locking mechanism of the mounting plate 46 in the warning device 20 will now be discussed. The normal position of the rod 30, the bracket 28, and the sign panel 22 is shown in FIG. 2, in which position the sign panel 22 is substantially flush with a mounting panel 112 and the rod 30 is in contact with, but has not actuated, the switch unit 26. If the sign panel 22 is now pushed inwardly by an operator, the rod 30 will also move toward the switch unit 26 and will push a switch lever 114 downwardly so as to actuate the switch and change the normally-open or normally-closed position thereof. When the panel 22 is released by the operator, a suitable spring 116 of the unit 26 will again urge the rod 30 and the sign panel 22 outwardly to the position shown in FIG. 2. The rod 30 and the sign panel 22 cannot move outwardly beyond the position shown in FIG. 2, however, because the wire spring 60 is urged against a flattened portion 118 of the operating rod 30 and resists outward movement thereof when the spring 60 contacts a shoulder at the end of the flattened portion 118, which occurs when the rod 30 and the sign 22 are in the flush position of FIG. 2. However, the shoulder at the end of the flattened portion 118 is slanted so that the sign panel 22 and the rod 30 can be moved outwardly when enough force is applied. An operator can apply this additional foroe simply by grasping the sign panel 22 by finger-nail recesses 17A) suitably formed in the ends thereof. When one of the lamps 40 is to be changed, the sign panel 22 is pulled outwardly, along with the rod 30, until the pin 94 is moved outwardly through the opening 102 and the central openings formed by the notches 72 until it abuts the bottom of the plate 62, at which point it can go no further, being larger than the central opening 64 of the plate 62. In this position, the pin 94 is within the opening 92 of the elongate cam member 90. The sign panel 22 and the bracket 28 are then rotated 90' to the position shown in FIG. 3 so as to cause the cam member 90 also to rotate 90 to a position parallel to the longitudinal extent of the plate 46 and perpendicular to the long walls of the recesses 74. The springs 84 can then push the locking tangs 88 inwardly until they abut the sides of the cam member 90, in which position the legs 86 retract within the plate 46. The plate 46 is then free of the ridges 98 and the sign panel 22, the bracket 28, the rod 30, and the plate 46 with the lamps 40 can be removed completely from the housing 24. The defunct lamp 40 can then be pulled outwardly from the bottom of the plate 46 and a new one substituted therefor.

When the lamp unit is again to be inserted into the housing 24, it is pushed until the locking tangs 88 are again located below the projections 98 of the housing 24, after which the sign panel 22 and the bracket 28 are rotated to their original positions, which causes the rod 30, the pin 94, and the cam member 90' to again rotate to the position shown in FIG. 4, thereby overcoming the force of the springs 84 and urging the locking tangs 88 outwardly so that the legs 86 again extend outwardly below the projections 98. The sign panel 22, the bracket 28, and the switch-operating rod 30 can then be pushed inwardly to the position shown in FIG. 2.

When the lamp unit is being inserted into the housing 24, it will be understood that the sign panel 22 and the bracket 28 might be mistakenly rotated 90 in the same direction in which they were originally rotated so that the sign panel 22 and the indicia thereon would be upside down when the assembly is completed. To prevent this possibility from occurring, the rod 30 has a second flattened portion 122 thereon (FIGS. 2 and 7) which is in the same plane as the wire spring 60 when the sign panel 22 and the bracket 28 are in their outer positions, and which will lie against the wire spring 60 if the sign panel 22 and the bracket 28 are rotated in the wrong direction. If an attempt is then made to push the sign 22 inwardly, the spring rod 60 will engage an upper square shoulder 124 of the flattened portion 122 and prevent inward movement of the rod 30 as well as the bracket 28 and the sign 22. Also to prevent undesired inversion of the assembly, one end of the plate 46 has a groove 126 therein formed by aligned notches in the various layers, which groove clears an inwardly projecting tab 128 struck inwardly from a side wall of the housing 124. Thus, if the plate 46 is assembled improperly, the unuotched end thereof will strike the tab 128 so that it cannot be pushed farther into the housing 24 and assembled therewith. Thus, the plate 46, the rod 30, and the sign panel 22 cannot possibly be assembled incorrectly. Although the sections 70 of the layers 66 and 68 have notches at both ends, these are only provided to enable all of the sections 70 to be identical to facilitate manufacture thereof and they do not serve in any functional capacity.

When the lamp plate 46 is reassembled, the lamps 40 are moved inwardly against the lamp contacts 36 and the ground contact 38 to compress their respective coil springs 130 and 132. The springs 130 and 132 will then urge the plate 46 outwardly to aid in its removal from the housing 24. These springs in urging the plate 46 upwardly, also cause the legs '86 of the locking tang 88 to bear against the projections 98 of the housing 24 to prevent the plate 46 from vibrating and to keep the warning device 28 tight. However, when the sign panel 22 and the bracket 28 are pulled outwardly and rotated so as to turn the cam member 90 and release the locking tangs 88, the force of the springs 13!) and 132 acting upwardly on the plate 46 may cause sufficient frictional engagement between the legs 86 and the projections 98 that the force of the springs 84 will not be sufficient to move the tangs 88 inwardly. In such a case, when the sign 22 and the bracket 28 are rotated to the position of FIG. 3, they may be pushed inwardly very slightly so as to move the plate 46 inwardly slightly and free the legs 86 of the locking tangs 88 from the projections 98. The springs 84 then immediately force the legs 86 into the plate 46 to enable the removal thereof.

Referring more specifically to the lamp and ground contacts 36 and 38, the springs of the lamp contact 36 urge a contacting head 1134 (FIGS. 8 and 13) against the lamps 40, the contacting heads 134 having annular ridges 136 and central points 138 which dig into and assure maximum electrical engagement with central contacts 148 of the lamps 40. The contact heads 134 are mounted on rods 142 which extend through bushings 144 held by the partition 34. At the lower ends of the rods 142 are stops 146 which limit upward movement of the lamp contacts 36 caused by the action of the springs 130. The bushings 144 are electrically connected to the terminals 42, and the bushings, in turn, provide electrical connection through the rods 142, the heads 134, and the points 138 to the central contacts of the lamps 40.

The ground contact 38 is constructed similarly to the lamp contact 36 with a similar head, rod, stop member, and bushing. However, the rod of the contact member 38 is longer than the rod 142 of the lamp contact 36 because the contact member 38 engages the metal plate 104 which is electrically connected with the tubular housing I06 and the body of each lamp 40.

An additional feature of the present invention is the connection for the switch unit 26 which can be easily assembled with or separated from the housing 24 so that the unit 26 can be changed in a matter of seconds. This is particularly important in case any part of the switch unit 26 should fail or if it is desired to employ a different type of switch. Toward this purpose, the switch unit 26 has a U-shaped switch casing 148 with open ends (FIGS. 2, 3 and 9). An L-shaped hook 150, which is structurally integral with the rear wall 32 of the housing 24, extends over one end of the casing 148 and resilient ears 152, which are also structurally integral with the rear wall 32, snap over the opposite end of the casing 148 to hold the switch unit snugly in place adjacent the rear wall 32. The casing 148 also has a large opening which cooperates with a circular projection 154 which is structurally integral with the rear wall 32 to assure that the switch unit 26 will remain in proper alignment with the switch rod 30. Ordinarily, the switch unit 26 could be assembled with the hook 150 and the resilient ears 152 either as shown or rotated 180". If it is desired to prevent this, however, the casing 148 can have a small cutwardly extending projection 156 which enters a hole 158 in a flange 160 which is attached to and constitutes part of the rear wall 32. This prevents the possibility of improper assembly of the switch unit 26 with the housing 24. Of course, any other of the switch units 26 used with the housing 24, while having countless numbers of variations in operation and number of terminals, etc., all have the same type of switch casing 148 with spaced, open ends.

While warning devices heretofore known commonly have been mounted in panels similar to the mounting panel 112, they have not been capable of being removed and mounted from the front of the panel. However, the warning device according to the present invention is capable of being both removed and mounted from the front. As shown particularly in FIGS. 2, 3 and 10, this is made possible by means of a front flange 162 of the housing 24 and mounting members Or resilient mounting strips 164 which are slidably mounted on the side walls of the housing 24. When the device 20 is in place and aflixe-d to the panel 112, the front flange 162 engages the front or obverse face of the panel 112 and ends of the mounting strips 164 engage the rear face of the panel 112 so as to clamp the device 20 thereto. The strips 164 can be mounted on the housing 24 in a number of suitable ways, and as shown, are slidably held under straps 166 which are struck out from the sides of the housing. The strips 164 are moved against the rear of the mounting panel 112 by means of threaded ears or extensions 168 which are structurally integral with the rear end of the strips 164 and move in a longitudinal direction on threaded shanks of screws 170. As best shown in FIGS. 2 and 3, the screws 170 are rotatably held by the rear wall 32 and extend through the partition 34 so that the heads of the screws are accessible from the front of the panel 112 when the lamp plate 46 is removed. When the screws have right-hand threads and are driven in a clockwise direction, the ears 168 move toward the mounting panel 112 until the panel 112 is clamped tightly between the strips 164 and the front flanges 162.

When it is desired to remove the device 20 from the panel 112, the screws 170 are driven in the opposite direction which causes the ears 168, extending through openings 172, to move away from the panel. When the strips 164 move toward the panel 112, they are moved outwardly by cam members 174 so as to engage the panel 112 around the opening therein. Similarly, when moving away from the panel 112, the strips 164 move beyond the cam members 174 in order to be flat against the side walls of the housing.

When the strips 164 are flat against the sides of the housing 24, the entire warning device can be moved outwardly through the mounting panel 112. For re-assembly, the device is inserted through the opening in the panel until the flanges 162 contact the obverse face thereof. The screws 170 then are driven in a clockwise direction to cause the ears 168 to move toward the mounting panel 112 to force the ends of the strips 164 outwardly and to move them into engagement with the panel 112.

A modified mounting arrangement is shown in perspective in FIGS. 11 and 12. Accordingly, mounting members 176 with longitudinally extending flanges 178 are connected by a strap 180 by means of which the members 176 are slidably mounted on the side walls of the housing 24. The strap 180 also structurally connects the members 176 so that they can be pushed on or removed from the housing 24 together. When the members 176 are on the housing 24, they are moved toward the mounting panel 112 by means of separate ears 182 and screws 184 to clamp the warning device to the panel 112 between the front flange 162 and the panel-engaging ends of the members 176. The ears 182 and the screws 184 are eccentrically mounted with respect to the openings 172 so that when the screws are driven in the clockwise direction, the ears abut the sides of the openings or notches 186 in the members 176 and stop in alignment therewith. The members can then be moved toward the panel 112 by further turning of the screws. The members 176 can be removed from the housing 24 by turning the screws 184 in the opposite direction to swing the ears 182 into the housing 24 whereupon the warning device can be removed from the front of the panel; at the same time the members 176 are pushed off the rear of the housing.

This mounting arrangement is preferred in many installations because it enables a number of the devices 20 to be mounted in a single elongate opening or slot in a control panel or the like. This is made possible because the clamping flanges 178 extend around the housing 24 and thus above and below the upper and lower edges of the opening in which the device 20 is mounted. The flanges 178 thus cooperate with the edges of a slot or elongated opening and will clamp the device on the panel even though the opening has no side edges adjacent the device.

While warning devices heretofore known have commonly employed colored, translucent sheets or colored lamps with the indicia-bearing panel, the present device 20 employs a unique means for imparting color to the light transmitted through the sign panel 22. This device includes translucent, resilient, domes or covers 188, as

best shown in cross section in FIG. 13, which are of the same configuration as glass bulbs 190 of the lamp 40. The free, annular edge of each of the covers 188 forms an annular groove 192 which fits over an annular flange 194 of the tubular housing 106 and holds the cover in spaced relationship to the bulb 190, the cover being larger than the bulb. An air space established between the cover 188 and the bulb 190 enables the lamp 40 to burn at a lower temperature because more heat can be dissipated from the larger surface of the cover 188. In addition, the cover 188 also is cooler, being spaced from the hot bulb 190 so that there is less tendency for it to burn or melt. The cover 188 can be easily replaced, to change colors, for example, simply by pulling it from the housing 106 and snapping a new cover onto the flange 194. In addition, the lamp 40 can be replaced without disturbing the cover at all.

Various modifications of the above described preferred embodiment of the invention will be apparent to those skilled in the art and it is to be understood that such modifications can be made without departing from the scope of the invention, if within the spirit and tenor of the accompanying claims.

I claim:

1. In an illuminated warning device, in combination, a housing, a lamp mounting plate removably carried in said housing, latch means on said lamp mounting plate and said housing to removably retain said lamp mounting plate in a predetermined position of assembly relative to said housing, an operating rod extending into said housing, and through said lamp mounting plate, and mounted for reciprocatory and rotary movement relative thereto, said latch means being disengaged by a predetermined one of such movements of said operating rod, means on said rod for engagement with said lamp mounting plate in one rotated position of said rod for moving said lamp mounting plate relative to said housing for retrieving and seating said lamp mounting plate therein, switch means carried by said housing and operated by reciprocation of said rod relative to said lamp mounting plate, and a member attached to said rod at the forward end thereof and manually engageable from the front of said housing for reciprocating and turning said rod.

2. In an illuminated warning device, in combination,

A. a generally tubular housing having an open front end,

B. an insulating partition (I) fixed to and (2) extending across said housing rearwardly of the open end thereof,

C. at least one contact carried by said partition,

D. a lamp mounting plate (1) removably mounted in said housing and (2) extending generally parallel to said insulating partition in its mounted position therein,

E. cooperating means on said lamp mounting plate and said housing for preventing relative rotation between said lamp mounting plate and said housing,

F. at least one lamp on said lamp mounting plate l) engaged by said contact in the mounted position of said plate,

G. an operating rod (1) extending rearwardly through said lamp mounting plate,

(2) said rod being mounted in and guided by said lamp mounting plate for axial and rotary movements relative to said lamp mounting plate,

(3) said operating rod extending through said lamp mounting plate a distance such that the rearmost end of said operating rod extends through said insulating partition when said lamp mounting plate is in mounted position within said housing,

H. cooperating latch means on said housing and on the periphery of said mounting plate said latch means 9 being disengaged by a predetermined one of such movements of said operating rod,

I. cooperating means on said rod and said lamp mounting plate engaged by forward axial movement of said rod relative to said lamp mounting plate for withdrawing said lamp mounting plate forwardly out of said housing, and

J. means on the forward end of said operating rod manually engageable from the front end of said housing for rotating and axially moving said operating rod.

3. The combination of elements defined in claim 2, in which said cooperating latch means on said housing and on the periphery of said mounting plate is actuated by rotation of said operating rod.

4. The combination of elements defined by claim 2 in which said cooperating means on said rod and said lamp mounting plate includes means for disengaging said latch means.

5. The combination of elements defined in claim 2 in which said means on the forward end of said operating rod includes a translucent sign plate.

6. The combination of elements defined in claim 5 in which said translucent sign plate closes the open front end of said housing and the edges of said sign plate extend forwardly beyond the front edge of said housing, and a recess on at least one edge of said sign plate lying forwardly of the adjacent one of said front edges of said housing.

7. The combination of elements defined in claim 5 in which said translucent sign plate has a legend thereon, and cooperating means carried in said lamp plate and on said rod for preventing a longitudinal movement of said rod inwardly through said lamp plate in other than a single desired relative angular position of said rod and said plate.

8. The combination of elements defined in claim 2 in which the rearmost end of said operating rod extends through said insulating partition, and a switch carried by the rear of said housing and actuated by an inward movement of said operating rod relative to said lamp mounting plate, and said insulating partition.

9. An illuminated warning device according to claim 2 for mounting in a panel opening and in which said generally tubular housing has a peripheral flange at its forward end for engaging the front surface of a mounting panel around said panel opening, and comprising means slidably mounted on the exterior of said housing for engaging the rear surface of said mounting panel adjacent said panel opening and for clamping said flange against said panel, and means carried by said insulating partition and eugageable through the open front of said housing for moving said slidable means into clamping position.

10. The combination of elements defined in claim 9 in which said last means includes a rotatable threaded means and a nut mounted on said threaded means and extending laterally from said housing in one rotated position for engaging a rear end of said slidable means, and in another rotated position lying entirely within the margins of said housing.

11. The combination of elements defined in claim 2 and slidingly engageable means on said housing and said lamp plate for preventing insertion of said lamp plate into said housing in other than a selected relative angular position.

12. An illuminated warning device as defined in claim l1 in which said slidingly engageable means comprises an inwardly extending tab on a side wall of said housing and a relieved area on a side of said lamp plate.

13. In an illuminated warning device, the combination of a housing, a lamp mounting plate normally disposed in an operating position in said housing and removable therefrom, said plate having a central hole therethrough and a passage extending from the central hole to an edge thereof, a locking tang in said passage having a first retracted position in which it is substantially wholly within said passage and a second extended position in which it extends from said passage, a catch on said housing in alignment for engagement by said tang when in extended position for locking said plate in its operating position, a rod extending through the central hole in said lamp mounting plate, said rod being rotatable relative to said passage and camming means on said rod and rotatable therewith for moving said tang in said passage between the first and second positions thereof, whereby said locking tang is retracted or extended, and said lamp plate is fixed to or released from said housing by rotation of said rod.

14. The combination of elements defined in claim 13 and switch means carried by said housing, said rod being reciprocable in said housing, and means interposed between said rod and said switch means to operate said switch means by reciprocation of said rod relative to said housing.

References Cited in the file of this patent UNITED STATES PATENTS 2,605,374 Batcheller July 29, 1952 2,710,955 Hallerberg et al June 14, 1955 2,718,636 Harrington et al Sept. 20, 1955 2,825,896 Schellman et al Mar. 4, 1958 2,883,652 Ireland Apr. 21, 1959 2,890,445 Korry June 9, 1959 2,959,774 Arrasmith Nov. 8, 1960 2,961,631 Smith Nov. 22, 1960 3,019,428 Arrasmith Jan. 13, 1962 

1. IN AN ILLUMINATED WARNING DEVICE, IN COMBINATION, A HOUSING, A LAMP MOUNTING PLATE REMOVABLY CARRIED IN SAID HOUSING, LATCH MEANS ON SAID LAMP MOUNTING PLATE AND SAID HOUSING TO REMOVABLY RETAIN SAID LAMP MOUNTING PLATE IN A PREDETERMINED POSITION OF ASSEMBLY RELATIVE TO SAID HOUSING, AN OPERATING ROD EXTENDING INTO SAID HOUSING AND THROUGH SAID LAMP MOUNTING PLATE, AND MOUNTED FOR RECIPROCATORY AND ROTARY MOVEMENT RELATIVE THERETO, SAID LATCH MEANS BEING DISENGAGED BY A PREDETERMINED ONE OF SUCH MOVEMENTS OF SAID OPERATING ROD, MEANS ON SAID ROD FOR ENGAGEMENTS WITH SAID LAMP MOUNTING PLATE IN ONE ROTATED POSITION OF SAID ROD FOR MOVING SAID LAMP MOUNTING PLATE RELATIVE TO SAID HOUSING FOR RETRIEVING AND SEATING SAID LAMP MOUNTING PLATE THEREIN SWITCH MEANS CARRIED BY SAID HOUSING AND OPERATED BY RECIPROCATIONS OF SAID ROD RELATIVE TO SAID LAMP MOUNTING PLATE, AND A MEMBER ATTACHED TO SAID ROD AT THE FORWARD END THEREOF AND MANUALLY ENGAGEABLE FROM THE FRONT OF SAID HOUSING FOR RECIPROCATING AND TURNING SAID ROD. 